Mmfp 0901 05 Z Mustang 5 0 Turbo Boost Front View

The air conditioning line (rusty tube) on the passenger side should be secured to prevent it from contacting the header tubes and to keep it as far away from the heat source as possible. Before you install the header, you'll need to apply a thin coat of copper high-temperature silicone sealer on the header flange. No gasket is used here. We also opted to use a 3/8-inch header bolt with 5/16-inch heads to make installing the header easier.